The field of the present invention relates to the safety mechanisms of a firearm. Specifically, the invention relates to the internal safety mechanisms of firearms such as the M1911 80-Series hand firearm, which are designed for inhibiting the firearm's firing pin in the case where the weapon's hammer is in the cocked position, and the firearm is given a sudden impulse that may otherwise set off the hammer and accidentally fire a chambered round.
Since its initial development in the 1970's, the Colt M1911 70-Series pistol has come with two different safety mechanisms. The first safety mechanism is the standard external manual latch-safety, which prevents the trigger from being engaged when the latch is in the “on” position. The second mechanism is engaged through the grip safety, particularly the pistol's beaver tail. When the pistol is not being held, the beaver tail is not pushed in, which provides a means of blocking the trigger. However, when the pistol is gripped in the natural firing position, the safety is disengaged, and the trigger is allowed to be pulled and a round fired. A problem did result with the pistol despite these two features: if the hammer of the pistol was cocked back and a round was chambered, and the pistol was dropped or given some sort of impulse, then there was a chance that the hammer would still strike the safety pin, setting off the round.
In response, about a decade after the 70-Series was released, the M1911 80-Series was developed. This version had the same safety mechanisms as the 70-Series, with one addition: an internal firing pin safety. This remedied the problem of the 70-Series by providing a mechanism in which a safety pin (metal cylinder) would block the firing pin from striking the chamber. This will not allow any type of firing to occur until the trigger is actually pulled, which activates various lever mechanisms that lift the safety pin upwards, revealing a clearing through which the firing pin can travel and successfully set off the round.
Although this design solved one problem, it did not come without its cost. One problem this new safety mechanism has created stems from the fact that at least three different parts (often made of metal) had to be introduced into the firearm body. Since pulling the trigger initiates the movement of the parts, the user has to exert more force on the trigger in order to overcome both the inertia and rotational moment of inertia that each individual piece of the safety mechanism possesses. In addition, each piece dissipates more energy given by the trigger through frictional rubbing, which means the user must exert an even greater amount of force on the trigger in order to fire a round.
Because the user now needs to exert more force on the trigger, the result is a loss of firing accuracy. It is therefore apparent that there exists a need for an internal safety mechanism that prevents the firearm from firing if it is given a sudden impulse, while at the same time giving the user the luxury of not having to exert too much force on the trigger, ultimately resulting in a more accurate shot.